Nagios assumes that DataNode is deployed on all the host machine in your cluster. The Nagios server displays DataNode alert on all the host machines even if a particular slave machine does not host a DataNode daemon.
To see a list of known open issues in Ambari 1.2.2.5, use the following query:
http://s.apache.org/all_issues_fixed_1.2.2
or click here.
